Fluid channel valve for use with a disposable cartridge in extracorporeal circulations

ABSTRACT

A valve for the closure of fluid channels, in particular for use in disposable cartridges for extracorporeal circulations, having a valve body with a pressure channel, and a sealing cap, which can cooperate with the valve body in such a way that it closes off the end of the pressure channel on the valve body side against the surroundings. The valve is designed in such a way that a pressure chamber can be formed between the pressure channel and the sealing cap, and the sealing cap has a deformable sealing area for entry into a fluid channel in order to close the latter. The valve may be incorporated within a device for use with a disposable cartridge for at least one fluid channel.

This is a nationalization of PCT/EP01/09510 filed Aug. 17, 2001 andpublished in German.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a valve for the closure of fluidchannels, in particular for use with disposable cartridges forextracorporeal circulations, such as for example in dialysis.

2. Description of the Related Art

Such valves are used to permit or to stop the fluid flow in dialysissystems. So-called disposable cartridges or one-time cartridges includein the cartridge body liquid channels which have to be opened or closeddepending on the requirement of the treatment, in order to convey orinterrupt the dialysis liquid. The liquid channels of the cartridge bodycan be closed off with a disposable film. The disposable cartridge isclosed with a counterpart on the device side, which counterpart ispressed, e.g. screwed down, with the disposable cartridge. In this way,the fluid channels of the disposable cartridge are closed off againstthe surroundings.

The components, which come into contact with blood or dialysis liquid asthe case may be, must satisfy high hygiene requirements.

With a disposable cartridge described in WO 94/20155, several fluidchannels are stamped in a body of this cartridge. At a point at which itis intended to be able to interrupt the fluid flow, projections areprovided in the fluid channel. The fluid channels of the body are closedwith a counterpart on the device side. In the area of the projections,this counterpart has flexible areas which can be pressed against theprojections in the fluid channel. In this way, the fluid flow can beinterrupted.

The problem of the present invention is to provide a valve and itsapplication, in particular for use with a disposable cartridge, whichare able to satisfy the hygiene requirements in a cost-effective andsimple manner.

SUMMARY OF THE INVENTION

This problem is solved according to the present invention with a valvefor the closure of fluid channels, in particular for use with disposablecartridges for extracorporeal circulations. The valve includes a valvebody with a pressure channel, and a sealing cap which cooperates withthe valve body in such a way that it closes off the end of the pressurechannel on the valve body side against the surroundings. The valve isdesigned in such a way that a pressure chamber can be formed between thepressure channel and the sealing cap, whereby the sealing cap has asealing area that is deformable in such a way that a fluid channel canbe closed thereby. The present invention is further directed to adisposable cartridge having at least one fluid channel, and to a devicefor use with such a disposable cartridge, in which the fluid flow ratethrough such channel is controlled by a valve of the type justdescribed.

The valve according to the invention has a valve body with a pressurechannel. A sealing cap co-operates with the valve body in such a waythat the end of the pressure channel on the valve body side closesagainst the surroundings. A pressure chamber can be formed between thepressure channel and the sealing cap, whereby a deformable sealing areaof the sealing cap can enter into the liquid channel in order to closethe latter.

The sealing cap can be rigidly connected to the valve body. A sealingcap which is detachable from the valve body, however, is particularlyuser-friendly and maintenance-friendly. This additionally simplifies andreduces the cost of the replacement of the sealing cap of importance forhygiene.

The valve function can easily be monitored by checking the pressure inthe pressure channel of the valve. By applying an excess pressure on thepressure channel, the liquid channel is closed by the stretching of thedeformable area. Simple venting in the pressure channel or theapplication of a partial vacuum opens the valve. The deformable valvecap provides for a good tolerance compensation both with the depth ofthe channel as well as with lateral misalignment of the valve withrespect to the liquid channel.

Finally, the overall, simply constructed valve unit can easily bereplaced. A malfunction of the valve accordingly does not require therepair or replacement of the whole device or counterpart of thedisposable cartridge on the device side, but only of the valveconcerned.

A preferred form of embodiment of the valve includes a fixing device forfixing the valve body in a housing. With the aid of such a fixingdevice, the valve can easily be inserted into the counterpart of adisposable cartridge on the device side. Spring snap rings or clampingdevices, for example, are conceivable as a fixing device. A simplearrangement includes a lock nut, which can be screwed up to the outerwall of the pressure channel, which is inserted through a body wall ofthe counterpart of the disposable cartridge on the device side.

A seal can be provided, which serves to seal the pressure chamberagainst the surroundings when the valve body is fixed in the housing. Itis particularly advantageous for a sealing surface also to be providedon the valve body, which sealing surface is surrounded by the sealingcap itself in such a way that the sealing cap is pressed on this sealingsurface when the valve body is being fixed. A separate adjustment of theseal when fixing the valve body in the housing is then no longernecessary. The seal is also already correctly positioned when thesealing cap is fitted on the valve body.

The sealing cap can be connected with the liquid channel by means of aseparate seal. A simple arrangement, however, makes provision such thata shoulder is provided on the sealing cap of the valve according to theinvention, which shoulder can be pressed against the edge of the liquidchannel in order to guarantee a suitable seal. With this form ofembodiment, only the valve has to be aligned with respect to the fluidchannel in order to guarantee an adequate seal.

In an advantageous development, the sealing cap has a projection, whichrestricts direct contact of the valve body with the sealing area of thesealing cap. The loading on the cap when the sealing area is pressedonto the channel is reduced by such a projection. The movement of thesealing area is not, however, impaired by the formation of a projection.

The valve according to the invention can be used in various applicationsfor the opening and closing of fluid channels. Due to its simplicity andreliability, however, the arrangement can be used to particularadvantage for controlling a fluid channel in a disposable cartridge indialysis.

The device according to the invention for use with a disposablecartridge has at least one valve according to the invention forcontrolling the fluid flow rate in at least one fluid channel of thedisposable cartridge. Alternatively, a device according to the inventionfor use with a disposable cartridge has a housing for a valve accordingto the invention, such that the valve according to the invention can beused for closing a fluid channel of the disposable cartridge.

A disposable cartridge according to the invention with at least onefluid channel, whose flow rate must be able to be controlled, thusrequires no housings or valve seats on the disposable cartridge side toallow it to be used with a device according to the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A form of embodiment of the valve according to the invention and itsapplication in a disposable cartridge are explained in the followingwith the aid of the appended figures.

They show:

FIG. 1 the cross-section through a valve according to the invention in adiagrammatic view and

FIG. 2 the valve of FIG. 1 according to the invention in use in adisposable cartridge, indicated solely diagrammatically.

FIG. 1 shows valve 1 in a sectional view, which is rotation-symmetricabout a vertical axis. Valve 1 consists of a valve body 2 with apressure channel 4, which ends in a pressure chamber 16. A sealing cap 6with a deformable area 8, which bounds pressure chamber 16, is placedover valve body 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Further scope of applicability of the present invention will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specificexamples, while indicating preferred embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description.

Pressure channel 4 of valve body 2 is designed elongated, so that it canbe inserted, for example, through the body or a wall of a counterpart ofa disposable cartridge on the device side and can be screwed down withlock nut 18. A thread (not drawn) is provided for this on the outer wallof pressure channel 4. Valve body 2 has sealing surfaces 20 for sealingvalve body 2 in the counterpart of the disposable cartridge on thedevice side. Sealing cap 6 includes protruding bulges 10, which surroundvalve body 2 in such a way that they lie adjacent to sealing surfaces 20and are pressed when the valve is assembled.

The upper area of valve 1 in FIG. 1 is the area on the fluid channelside. For the fitting into the fluid channel, a shoulder 12 of sealingcap 6 is provided, such as will be explained by reference to FIG. 2. Aprojection 14 of sealing cap 6 lies on the end of valve body 2 on thefluid channel side.

A valve according to the invention is shown dramatically in use in FIG.2. 28 designates the part of the disposable cartridge body indiagrammatic representation in which liquid channels 22 are stamped. 30designates the corresponding counterpart of the disposable cartridgebody on the device side, which is pressed against part 28 with fixingmeans (not shown) known per se.

Valve 1 is inserted into a suitably shaped housing 26 of counterpart 30and screwed down with lock nut 18. Shoulder 12 lies adjacent to theedges of liquid channel 22. The movement of deformable area 8 when anexcess pressure or partial vacuum is applied or with venting of pressurechannel 4 is indicated by arrow 24. 32 indicates the direction in whichthe pressure is applied in order to close the valve. In FIG. 2, housing26 in counterpart 30 is rotation-symmetric about pressure channel 4 ofvalve 1, whilst liquid channel 22 in the example shown extends at rightangles to the plane of the figure.

Diverging from the form of embodiment shown, a cut-out for accommodatingshoulder 12 can be provided either in disposable cartridge body 28 or incounterpart 30 on the device side. It is also possible for shoulder 12to be accommodated in a suitable opening in a cover mat located betweendisposable body 28 and counterpart 30 on the device side.

For the sake of clarity, FIG. 2 does not show a disposable film knownper se, which closes off fluid channel 22 against the surroundings. Sucha disposable film can be fixed on the side of disposable body 28 that ispressed with counterpart 30 on the device side. The disposable film mustbe sufficiently flexible, such that it can follow the deformation ofsealing area 8.

For the operation of valve 1 with a disposable cartridge, valve body 2is inserted through housing 26 of counterpart 30 on the device side, sothat pressure channel 4 extends through counterpart 30. Lock nut 18 istightened up so that sealing bulges 10 create a seal between valve body2 and counterpart 30. By simply screwing up lock nut 18, a tight andreliable connection of valve 1 with counterpart 30 of the disposablecartridge on the device side is thus provided.

Counterpart 30 with valve 1 is pressed with disposable cartridge body28, whereby sealing cap 6 with shoulders 12 fits tightly with the edgesof liquid channel 22. By pressing counterpart 30 on disposable cartridgebody 28, several valves 1 are as a rule simultaneously fitted intocorresponding liquid channels 22 at the desired points.

The dialysis liquid, for example, flows through fluid channel 22 in theopened state of valve 1. If excess pressure is applied on pressurechannel 4 in the direction of arrow 32, sealing area 8 is deformed intoliquid channel 22 until the latter is finally closed. The loading on thecap when pressing on the channel is minimised by projection 14, withoutthe movement of the deformable area being significantly impaired. If adisposable film is provided on the disposable body, said disposable filmis deformed together with the sealing cap into the liquid channel.

If fluid channel 22 is to be opened again, pressure channel 4 is ventedand deformable area 8 of sealing cup 6 is relaxed. By applying a partialvacuum on pressure channel 4, deformable area 8 is placed against theconvex curvature of pressure chamber 16 and correspondingly increasesthe cross-section of fluid channel 22. By simply applying or removing apressurisation on pressure channel 4, therefore, the flow rate throughfluid channel 22 can be controlled.

When the disposable cartridge is removed, the valve can be removed orreplaced simply by loosening lock nut 18, e.g. for maintenance or in theevent of malfunction.

The sealing cap is a simple low-cost shaped part, which on account ofits closed design can easily be cleaned and thus satisfies the hygienerequirements in dialysis, but which can also easily be replaced whennecessary.

When the disposable cartridge is closed again by fixing counterpart 30on body 28, the valve fits in very well by pressing shoulder 12 with theedge of fluid channel 22. On account of the elastic stretching ofdeformable area 8 of sealing cap 6, there is a very good tolerancecompensation both in the depth of channel 22 as well as in respect oflateral misalignment, without a significant additional expenditure offorce arising. Deformable area 8 guarantees that only small forces arerequired to block fluid channel 22.

The invention being thus described, it will be apparent that the samemay be varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be recognized by one skilled in the art areintended to be included within the scope of the following claims.

1. A valve for the closure of a fluid channel in a disposable cartridgefor extracorporeal circulations, comprising a valve body having apressure channel, and a sealing cap that cooperates with the valve bodyto close off said pressure channel at a proximal end of said valve bodyagainst the surroundings, said valve being designed such that a pressurechamber can be formed between the pressure channel and the sealing cap,said sealing cap having a sealing area, a shoulder, side portions thatgenerally surround said valve body, and an inwardly directed projectionat said valve end adjacent said fluid channel that extends over an uppersurface of said valve body to prevent direct contact of the valve bodywith the sealing area, said sealing area being deformable in such a waythat said fluid channel can be closed thereby and said shoulder fittingadjacent edges of said fluid channel.
 2. A device for extracorporealcirculations comprising: a disposable cartridge having at least onefluid channel configured to receive dialysis liquid; a valve forcontrolling the fluid flow rate in said fluid channel, said valveincluding a valve body with a pressure channel and a sealing cap havinga shoulder in a fixed relationship adjacent edges of said fluid channel;a counterpart component having a housing formed therein for said valvethat is generally aligned with said fluid channel when a face of saidcounterpart component is pressed against a face of said cartridge toassemble said device, said shoulder being compressed between said faceswhen said device is assembled; said valve body being generally enclosedwithin said housing, and said sealing cap surrounding at least part ofthe valve body to close off an end of the pressure channel proximal tosaid valve body against the surroundings, and form a pressure chamberbetween the pressure channel and the sealing cap, said sealing caphaving a sealing area that is deformable to close said fluid channel tocontrol dialysis liquid flow therethrough during extracorporealcirculations.
 3. The device according to claim 2, wherein said housingin said counterpart component is rotation-symmetric about the pressurechannel of said valve.
 4. The device according to claim 2, wherein thefaces of said disposable cartridge and said counterpart component aregenerally parallel with one another.
 5. The device according to claim 2,wherein the sealing cap has an inwardly directed projection configuredto prevent direct contact of the valve body with the sealing area. 6.The device according to claim 2, wherein said sealing cap has sideportions that surround an outer wall of said valve body to contact aninner wall of said housing, said side portions being generallyperpendicular to said shoulder and to a space formed between saidcounterpart component and said cartridge by said shoulder.
 7. The deviceaccording to claim 6, wherein a protruding bulge is provided at an endof said sealing cap side portions, said protruding bulge being pressedagainst a sealing surface on the valve body when the valve body issecured in the housing, said sealing surface and said bulge beinggenerally perpendicular to said side portions.
 8. The device accordingto claim 2, further comprising a fixing device configured to fix saidvalve body in said housing, said fixing device including a fasteningcomponent coupled to a protruding end of said pressure channel, saidfastening component being in abutment with a side of said counterpartcomponent distal from said disposable cartridge.
 9. A device forextracorporeal circulations comprising a disposable cartridge with atleast one fluid channel, a counterpart component pressed against saiddisposable cartridge and having a housing formed therein that isgenerally aligned with said fluid channel, and a valve inserted in saidhousing within said counterpart component for controlling fluid flowrate in said fluid channel, said valve having a valve body with apressure channel therethrough and a sealing surface on an outer wall,and a sealing cap with side portions that surround at least part of saidvalve body within said housing, said side portions including aprotruding portion that is pressed against said sealing surface of saidvalve body when said valve body is secured within said housing to sealsaid valve body in said counterpart component, said sealing cap furtherincluding a deformable sealing area that extends outside said housing toeffect closure of said fluid channel.
 10. The device according to claim9, wherein said sealing cap cooperates with the valve body to close offan end of the pressure channel proximal to said valve body against thesurroundings, said valve being configured such that a pressure chambercan be formed between the pressure channel and the sealing cap to deformsaid sealing area and close said fluid channel.
 11. The device accordingto claim 10, further comprising a fixing device for fixing the valvebody in the housing.
 12. The device according to claim 11, wherein saidfixing device includes a fastening component coupled to a protruding endof said pressure channel, said fastening component being in abutmentwith a side of said counterpart component distal from said cartridge.13. The device according to claim 12, wherein said sealing surface isgenerally perpendicular to said sealing cap side portions.
 14. Thedevice according to claim 10, wherein the sealing cap is detachable fromthe valve body.
 15. The device according to claim 9, wherein saidhousing in said counterpart component is rotation-symmetric about thepressure channel of said valve, and said valve body surrounded by saidside portions generally corresponds in size to an opening in saidcounterpart component defined by said housing.
 16. The device accordingto claim 9, wherein said sealing cap includes a shoulder compressedbetween said counterpart component and said disposable cartridgeadjacent edges of said fluid channel.
 17. The device according to claim16, wherein said side portions extend generally perpendicular to saidshoulder along an inner wall of said housing.
 18. The device accordingto claim 17, wherein the sealing cap has a projection that extendsinwardly from said shoulder to cover an upper surface of said valve bodyand prevent direct contact of the valve body with the sealing area. 19.The device according to claim 16, wherein interfacing surfaces of saiddisposable cartridge and said counterpart component are generallyparallel with one another and said shoulder fits between said surfacesto maintain a spacing therebetween in areas apart from said valve whilesealing said fluid channel from said spacing.